I'm using VL6 Standard and I switched to LXDE just so I could find the answer for you.

If your LXDE works like the one in VL6, right-clicking on your desktop should bring up a menu with Desktops as one of the choices. Click on Desktops and you should see a list of your desktops. Under that list is Add New Desktop. Click on that and you should get another one. Another "box" should appear in the pager. Repeat if you want more.

If this doesn't work, I don't know what else to suggest because I'm using a different version of VectorLinux and I use XFce. If nobody comes up with the answer, try googling. --GrannyGeek